Organic laser for measurement

ABSTRACT

This invention provides a system and a method for measuring displacements and movements, particularly for measuring very fine displacements and very minute movements. Position, vibration and rotational/angular movements can be measured. One or more directions can be measured simultaneously. In one embodiment, the system comprises one or more measuring means at least configured to tune multiple color emissions from a laser comprising an organic laser and/or a cascaded organic laser, such that the tuned multiple color emissions of the laser are used in measurements. The system is scalable in order to support measurement across a very large space. Optionally, the system further comprises a thin film laser generating device for generating said laser, blue and green emission organic semiconductors for generating said organic laser, and laser sensors for sensing said laser where said laser sensors comprise organic laser sensors and/or cascaded organic laser sensors.

CROSS-REFERENCE TO THE RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional patentapplication Ser. No. 61/978,985 filed on Apr. 13, 2014, which is herebyincorporated by reference in its entirety.

FIELD OF THE INVENTION

This invention relates a method to tune multiple color emissions fromorganic laser and using such tuning to measure displacements andmovements. More particularly, the present invention relates to the useof cascaded organic laser to produce tunable multiple color emissionsthat is used to measure very fine displacements and movements inphysical spaces. The invention is used for providing accurate and finemeasure of displacements and movements in physical spaces forapplications wherein such fine movements are of interest.

BACKGROUND OF THE INVENTION

In many high precision systems, any minute displacements or finemovements in its structures and guidance systems can result inundesirable results at its best of times, or disastrous results at itsworst of times. In such systems, such as the Very Large Hadron Collider(VLHC), which is a superconducting proton-to-proton collider comprisinga 27 kilometers synchrotron designed to collide two opposing particlebeams of protons, any minute displacements of its complex arrays of beamguides will result in major and very costly failures. Currently thereare very few techniques that can provide accurate monitoring anddetection of such minute displacements in such systems. In the few priorart that exists, such systems are either very complex to implementand/or cannot be up-scaled to monitor a large establishment.

There is a need for a simple, effective, accurate and scalable method ofdetecting, monitoring and measuring even very minute displacements andfine movements of systems in physical spaces.

Citation or identification of any reference in this section or any othersection of this application shall not be construed as an admission thatsuch reference is available as prior art for the present application.

SUMMARY OF THE INVENTION

The present invention provides a method to tune multiple color emissionsfrom organic laser and using such tuning to measure displacements andmovements. In a first aspect of the present invention there is provideda use of cascaded organic laser to produce tunable multiple coloremissions that is used to measure very fine displacements and minutemovements in physical spaces. In a second aspect of the presentinvention there is provided a method to obtain accurate and fine measureof displacements and minute movements in physical spaces forapplications wherein such movements are of interest. In a third aspectof the present invention there is provided a system to provide suchdetection, monitoring and measurement in a scalable manner across largephysical and/or geographical spaces.

The method for measuring displacements and movements comprises tuningmultiple color emissions from a laser such that the tuned multiple coloremissions of the laser are used to measure said displacements and saidmovements. Said laser comprises an organic laser and/or a cascadedorganic laser. Said measured displacements include very finedisplacements and said measured movements include very minute movements.Furthermore, said method is scalable in order to support the measuringof displacements and movements across one or more physical/geographicalspaces including very large physical and/or geographical spaces.

The system for measuring displacements and movements comprises one ormore measuring means at least configured to tune multiple coloremissions from a laser such that the tuned multiple color emissions ofthe laser are used to measure said displacements and said movements.Said laser comprises an organic laser and/or a cascaded organic laser.Said measured displacements include very fine displacements and saidmeasured movements including very minute movements. In addition, saidsystem is scalable in order to support the measuring of displacementsand movements across one or more physical/geographical spaces includingvery large physical and/or geographical spaces.

Throughout this specification, unless the context requires otherwise,the word “include” or “comprise” or variations such as “includes” or“comprises” or “comprising”, will be understood to imply the inclusionof a stated integer or group of integers but not the exclusion of anyother integer or group of integers. It is also noted that in thisdisclosure and particularly in the claims and/or paragraphs, terms suchas “included”, “comprises”, “comprised”, “comprising” and the like canhave the meaning attributed to it in U.S. Patent law; e.g., they canmean “includes”, “included”, “including”, and the like; and that termssuch as “consisting essentially of” and “consists essentially of” havethe meaning ascribed to them in U.S. Patent law, e.g., they allow forelements not explicitly recited, but exclude elements that are found inthe prior art or that affect a basic or novel characteristic of thepresent invention.

Furthermore, throughout the specification and claims, unless the contextrequires otherwise, the word “include” or variations such as “includes”or “including”, will be understood to imply the inclusion of a statedinteger or group of integers but not the exclusion of any other integeror group of integers.

Other definitions for selected terms used herein may be found within thedetailed description of the present invention and apply throughout.Unless otherwise defined, all other technical terms used herein have thesame meaning as commonly understood to one of ordinary skill in the artto which the present invention belongs.

Other aspects and advantages of the present invention will be apparentto those skilled in the art from a review of the ensuing description.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects and features of the present invention willbecome apparent from the following description of the present invention,when taken in conjunction with the accompanying drawings.

FIG. 1 shows (a) Cross-section of cascaded films with PFO (120 nm), F8BT(250 nm), optically clear adhesive (60 μm), and silica (1 mm); (b) ASEmeasurement configuration, the cascaded films is pumped with Nd:YAGlaser (355 nm, 10 Hz) and the excitation area is 5 mm×300 μm; and theASE output is collected from the edge of the sample by the fiber coupledspectrometer.

FIG. 2 shows (a) Photoluminescence spectra of PFO and F8BT; (b)Transmittance of (i) PFO (120 nm, filled squares), (ii) F8BT (250 nm,filled circles), (iii) Optically Clear Adhesive (60 μm, open squares)and (iv) Cascaded PFO (120 nm)/F8BT (250 nm) films (open circles).

FIG. 3 shows the normalized ASE spectra in different positions from edgeof the sample with pumping power density at 0.53 mW/cm²; thecross-section of the receiving fiber with the position located; (b)Power dependence of PFO; (c) Power dependence of F8BT.

FIG. 4 shows the diagram of the CIE color space.

FIG. 5 shows the schematic illustration of remote position, vibration,and rotational-motion movement.

FIG. 6 shows the cascaded organic laser configurations.

FIG. 7 shows the optical sensor configuration (2-axis position andvibration measurements).

FIG. 8 shows the optical sensor configuration (3-axis position andvibration measurements).

FIG. 9 shows the optical sensor configuration (rotational motionmeasurement).

FIG. 10 shows the multiwavelength organic laser source for pump-probetest.

FIG. 11 shows the ratio (the peak intensity of PFO/the peak intensity ofF8BT) against distance graph and it showed the effective range: 2.2 mm(from 0.4 mm to 2.6 mm).

FIG. 12 shows normalized ASE spectra in different positions from edge ofthe sample with same pumping energy density at 247 μJ/cm²; D1 and D2 aredefined in FIG. 1, the white light representing the white light ASE withCIE coordinate (0.32, 0.35).

FIG. 13 shows the ratio (the peak intensity of PFO/the peak intensity ofF8BT) against distance graph and it showed the effective range: 2.2 mm(from 0.4 mm to 2.6 mm).

FIG. 14 shows the ASE spectra in different positions from edge of thesample with same pumping energy density at 247 μJ/cm².

DETAILED DESCRIPTION OF THE INVENTION

The presently claimed invention is further illustrated by the followingexperiments or embodiments which should be understood that the subjectmatters disclosed in the experiments or embodiments may only be used forillustrative purpose but are not intended to limit the scope of thepresently claimed invention.

Without wishing to be bound by theory, the inventors have discoveredthrough their trials, experimentations and research that to accomplishthe task of tuning multiple color emissions from an organic laser andusing such tuning to measure displacements and movements.

Tunable Color Emission: White Light Amplified Simultaneous Emission

Semiconducting (conjugated) polymer draws much attention nowadays as itis a promising possible application. With increasing emissionefficiency, excited emission such as ASE (amplified spontaneousemission) and lasing have been achieved. Recently, the white ASE hasbeen reported but with one ASE spectrum and one much broader spectrum.In this invention, the gain media in optical amplifiers will be studied.Two individual shape ASE spectra in one sample will be demonstrated.

A first aspect of the present invention aims at getting white light ASEwith two different color ASE spectra that have near-equal spectralprofile. Two materials, Poly (9,9-di-n-dodecylfluorenyl-2,7-diyl) (PFO)and Poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(benzo[2,1,3]thiadiazol-4,8-diyl)](F8BT) were selected. The corresponding peaks of PFO and F8BT are at 450nm and 575 nm, respectively, and the full width half maximum are 5 nmand 10 nm. Therefore, they are suitable to be combined to give a whiteASE. A PFO thin film was first deposited onto a glass substrate, andthen a high transmittance optical clear adhesive (over than 90%transmittance in visible range) was added as a spacer that separate itfrom the F8BT thin film. The sample successfully demonstrated whitelight ASE when pumped by a 355 nm third harmonic laser from Nd:YAG. TheCIE coordinate achieved is (0.36, 0.45) and a comparable threshold.

In conclusion, it is shown that a simple thin film configuration thatcan produce white light ASE was achieved and it is possible to tune theCIE coordinate from the thin film thickness. Such device can be used asstrong white light source in spectroscopy experiments.

Tunable Color Emission from Cascaded Amplified Spontaneous Emissions inOrganic Thin Films

Since the demonstrations of the semiconducting (conjugated) polymerlight emitting diodes, semiconducting (conjugated) polymer draws lots ofattentions as promising gain materials in lasing application. In thesecond aspect of the present invention, we demonstrated the AmplifiedSpontaneous Emission (ASE) processes can be used to realize tunableemission spectra of a cascaded organic thin film system, consisting ofblue and green emission organic semiconductors. When the cascaded filmswere pumped by a pulsed UV emission laser, the directional emission ofASE from the two kinds of materials are partially overlapped in the farfield. The emission spectra can be tuned almost linearly in the CIEcoordinates from (0.42, 0.55) to (0.18, 0.11) by spatially choosing theemission signals. The method shown herein can be used to design apolychrome light source for display, bio-imaging and relatedapplications.

Experimental Details

Sample Structure (FIG. 1a ):

-   -   Silica/PFO/Optically Clear Adhesive(OCA)/F8BT/Silica.

Condition:

-   -   Using Toluene as solvent and Spin-coating for fabrication.    -   PFO (Poly(9,9-di-n-dodecylfluorenyl-2,7-diyl): 16 mg/ml, 120 nm.    -   F8BT        (Poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(benzo[2,1,3]thiadiazol-4,8-diyl)]):        23 mg/ml, 250 nm.    -   Optically Clear Adhesive (OCA): 60 μm, n=1.48.

Experiment (FIG. 1b ):

-   -   Pumped by Nd:YAG laser (λ=355 nm, repetition rate: 10 Hz and        pulse width: 5 ns).    -   Excitation Area: 5 mm×300 μm.    -   The spontaneous emission and ASE signals from Sample were        collected at edge of the device and analyzed by a fiber coupled        spectrometer (Ocean Optics, USB 4000).    -   Using a photodiode to monitor and calibrate the pumping power of        the laser.

Experimental Results

The photoluminescence (PL) spectra of PFO and F8BT (FIG. 2a ):

-   -   Under a condition of being pumped by He—Cd laser (λ=325 nm).

The transmission efficiency of the optical adhesive, PFO, F8BT andPFO/F8BT cascaded films (FIG. 2b ):

-   -   Showing that the wavelength of the pump laser (355 nm) is        located in absorption region of both PFO and F8BT films.

ASE Measurement:

-   -   The ASE signals from PFO (ASE_(PFO)) and F8BT (ASE_(F8BT)) were        separated in the near field by the OCA, and the two directional        emissions were then imaged in the far field.    -   As shown in FIG. 3a , the total ASE spectra (pumping density:        0.53 mW/cm²) strongly depend on the spatial distribution of the        two overlapped emission beams.

The power dependence ASE at D1 and D2 positions (FIG. 3b , FIG. 3c ):

-   -   At low pumping power, the spontaneous emission in both PFO and        F8BT are dominant. By increasing the pumping power, the PL        spectra show clearly the thresholds of ASE process (0.37 mW/cm²        for PFO and 0.43 mW/cm² for F8BT).

Commission Internationale d'Eclairage (CIE) Coordinates (FIG. 4):

-   -   The color of the output ASE changes as the collection fiber        moves from D1 to D2.    -   The black dots represent the CIE coordinate of the specific        spectrum.    -   The CIE coordinates can be tuned from (0.42, 0.55) to (0.18,        0.11) with a linear relation. The color of the ASE emission        passes very close to the centre of CIE coordinates (0.32, 0.35),        which is for white light emission.

Findings

We have demonstrated a device made of cascaded organic semiconductingfilms. The ASE from the two kinds of materials can be obtained afterbeing pumped by a single laser beam. The tunable emission spectrum ofASE was achieved in the far field with tunable CIE coordinates from(0.42, 0.55) to (0.18, 0.11). The device has great potential to be usedas a polychrome light source in display, imaging and bio-sensingapplications.

Remote Measurement Schemes

The schematic illustration is shown in FIG. 5. Cascaded organic lasersensors (COLS) at different locations are connected to a central officeby optical fibers for remote measurement of different subjects. Itfollows that the real-time information from the subjects can be directlytransferred to the central office, and the central office cansimultaneously monitor all the subjects in a single location. For themeasurement, the central office provides pump laser, optical spectrumanalyzer, RF spectrum analyzer, optical switches, photodetectors andoptical filters. It is worthy to indicate that the COLS is a passivedevice, and no electrical power or energy source is needed, so that theCOLS can be used at any location without a need for power supply.Furthermore, the remote measurement scheme is scalable in the sense thatmore number of COLS may be installed from time to time in order toperform measurement across one or more physical/geographical spaces,which may include very large physical and/or geographical spaces.

FIG. 6 shows the cascaded organic laser configurations. There are 2types of cascaded organic lasers, comprising organic thin films as shownin FIGS. 6 (a) and (b), respectively. The first type shown in FIG. 6a isfor measurement of x and z directions OR y and z directions, whereas thesecond type shown in FIG. 6b is for measurement of x, y and zdirections.

Examples of Organic Laser Sensors

(a) Sensor for 2 Axis Position and Vibration Measurement

FIG. 7 shows the optical sensor configuration of a COLS for 2 axisposition and vibration measurement. In the sensor, the multiwavelengthlaser beams or Amplified Spontaneous Emission (ASE) are spatiallyoverlapped and focused on an optical fiber. Since the optical fiber hasa defined aperture, it can control the measurement accuracy of thesensor. When the subject moves along x- or y-axis as shown in FIG. 7,the optical fiber can receive the different intensity changes atwavelengths A and B. With calibration of the intensity distribution at Aand B against position, real-time displacement of the subject can bemonitored.

In addition, when the subject moves along the z-axis, the optical fiberwill receive the intensity changes at both wavelengths A and B. Again,with calibration of the intensity changes at A and B againstdisplacement, real-time displacement of the subject at the z directioncan be monitored.

Besides the position measurement, by using the RF spectrum analyzer,photo-detector and optical filter, the vibration frequency of thesubject can also be directly detected at both the z-axis and the x- ory-axis.

(b) Sensor for 3-Axis Position and Vibration Measurements

FIG. 8 illustrates the optical sensor configuration of a COLS for 3-axisposition and vibration measurements.

FIG. 8(a) shows the cross-sectional view of the organic laser and fiberposition, in which the organic laser is installed at 45 degree againstthe x-axis and y-axis.

FIG. 8(b) shows the optical sensor configuration.

(i) x-Axis Monitoring

The wavelength pair A and B is assigned for measuring the x-axisposition and vibration. When the subject moves along the x-direction,the position of optical fiber is changed. The received optical signalsat wavelengths A and B are also changed accordingly. Therefore, withcalibration of the intensity changes at A and B against position, thereal-time displacement of the subject can be monitored. The opticalsignal changes are depicted in FIG. 8(c).

(ii) y-Axis Monitoring

The wavelength pair A′ and B′ is assigned for measuring the y-axisposition and vibration. When the subject moves along the y-direction,the position of optical fiber is changed. The received optical signalsat wavelengths A′ and B′ are also changed accordingly. Therefore, withcalibration of the intensity changes at A′ and B′ against position, thereal-time displacement of the subject can be monitored. The opticalsignal changes are depicted in FIG. 8(c).

(iii) z-Axis Monitoring

At the same time, the intensities of wavelengths A, A′, B and B′ arealso sensitive to the z-axis position change. When the subject movesalong the z-direction, the received optical signals at wavelengths A,A′, B and B′ are changed as shown in FIG. 8(c). Therefore, withcalibration of the intensity changes for A, A′, B and B′ againstposition, the real-time displacement of the subject can besimultaneously monitored.

(iv) Vibration Measurement

Again, by using the RF spectrum analyzer, photo-detector and opticalfilters, the vibration frequency of the subject at x, y and z directionscan also be monitored.

(c) Sensor for Rotational Motion Measurement

FIG. 9 shows the optical sensor configuration for rotational motionmeasurement.

FIG. 9(a) illustrates the cross-sectional view of the sensor, in whichthe organic-laser thin film pairs AA′ and BB′ are aligned with respectto the optical fibers F1 and F2, respectively. The rotation axis islocated between optical fibers F1 and F2. FIG. 9(b) shows the opticalsensor configuration for rotational motion measurement.

Clockwise Rotation Measurement

When the subject is rotated clockwise about the rotation axis, bothfiber F1 and F2 can receive the intensity changes at wavelengths AA′ andBB′, respectively. Under this situation, the received intensities atwavelengths A and B are increased, and received intensities atwavelengths A′ and B′ are decreased. FIG. 9(c) shows the opticalsignals.

Anti-Clockwise Rotation Measurement

When the subject is rotated anti-clockwise about the rotation axis, bothfiber F1 and F2 can receive the intensity changes at wavelengths AA′ andBB′, respectively. Under this situation, the received intensities atwavelengths A and B are decreased, and received intensities atwavelengths A′ and B′ are increased. FIG. 9(c) shows the opticalsignals.

Therefore, with the calibration of the intensity changes for A, A′, Band B′ against angle, real-time angular change of the subject can bemeasured. In addition, by using the RF spectrum analyzer, photo-detectorand optical filters, the angular frequency of the subject at therotation axis can also be monitored.

(d) Multiwavelength Pulsed Organic Laser for Remote Pump-Probe Test

Two configurations of multiwavelength pulsed organic laser source areshown in FIGS. 10 (a) and (b), in which FIG. 10(a) provides a cascadedorganic lasers in linear architecture, and FIG. 10(b) provides acascaded organic lasers in two-dimensional architecture.

In general, when using pulsed laser as an optical pump, the organiclaser will emit optical pulse accordingly. It follows that, in ourconfigurations, when the optical pump pulse is incident on the laserdevice, it will be sequentially transmitted through the cascaded organicthin films. Therefore, each thin film is excited by the pump pulse atdifferent time slot. As a result, each thin film will emit the laserpulse with a sequential time delay. The time sequences of output laserpulses are shown in FIG. 10 (a). By precisely controlling the silicathickness of less than 1 mm, the output pulse delay-time can beprecisely controlled at pico- to femto-second range. These pulse trainscan be used for pump-probe tests, such as time-resolved infraredspectroscopy, transient-absorption spectroscopy, and time-resolvedfluorescence spectroscopy. Furthermore, the new 2-dimensionalconfiguration shown in FIG. 10 (b) can also generate a pulse pair in asingle time slot. The delay time between each pulse pair can also beprecisely controlled at pico- to femto-second range. The output pulsesequence is shown in FIG. 10 (b). This multiwavelength pulsed outputshave potential applications in the multiple-pulse pump-probe test.

Experimental Details

We employed two different color materials in our experiment, the blueemission polymer PFO (Poly(9,9-di-n-dodecylfluorenyl-2,7-diyl) and greenemission polymer F8BT(Poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(benzo[2,1,3]thiadiazol-4,8-diyl)]).Those materials were purchased from Sigma-Aldrich. The molecule weightand polydispersity index of PFO are Mw≦20000 and ˜3.7, respectively. Theaverage molecule weight of F8BT is ˜10000-20000 and polydispersity indexis <3. Both of the two materials were dissolved in toluene solution withconcentrations of 16 mg/mL and 23 mg/mL, respectively. The polymer filmswere fabricated by spin-coating onto pre-cleaned fused silica substrateswith thickness of 120 nm and 250 nm, respectively. As shown in FIG. 1a ,the cascaded thin film system includes PFO and F8BT, which are boundedtogether via a 60 μm thick optically clear adhesive (OCA). The intentionof adding the OCA is to totally separate the two materials so as toprevent any mixing. It is because both materials use the same solvent,toluene, and they may penetrate into each other. The refractive index ofOCA is around 1.48, which is less than that of PFO and F8BT.

In the ASE experiment (FIG. 1b ), the PFO/F8BT cascaded films werepumped by third harmonic generation of Nd:YAG laser at wavelength λ=355nm with a repetition rate of 10 Hz and a pulse width of 5 ns. The laserbeam is firstly diverged by a concave lens, and then squeezed into astripe beam by a cylindrical lens. Finally, the stripe beam was focusedonto the device after cutting the non-uniform edges of the stripe laserspot using adjustable slits. The area size of the rectangular laser spotis 5 mm×300 μm. The spontaneous emission and ASE signals from PFO andF8BT were collected at edge of the device using the objective lens andanalyzed by a fiber coupled spectrometer (Ocean Optics, USB 4000). Thefiber coupled spectrometer also can be moved in x and y directions(shown in FIG. 1a ) for detecting the output intensity. In FIG. 1b , D1and D2 represent the highest intensity positions of PFO (450 nm) andF8BT (575 nm), respectively. In addition, a photodiode was used tomonitor and calibrate the pumping energy of the laser.

Results and Discussion

Before the experiment, we firstly tested the device's basic opticalproperty. In FIG. 2, we characterized the transmission efficiency of theoptical clear adhesive, PFO, F8BT and PFO/OCA/F8BT cascaded films. Itshows that the OCA and cascaded films have a high transmittance for thepumping laser (355 nm), so that the device is suitable for theexperiment.

The purpose of this optical sensor is to monitor and measure relativelysmall distance vibrations. Assume that there is an object to be detectedfor the vibration using this sensor. The sensor's operating principle isto first receive lasing spectra before and after the vibration, and thento calculate the peak ratios (or both peak intensities) between PFO andF8BT. Finally, using the ratios (or both peak intensities), we canextract the distances to find the vibration of the object. For theoptical sensor, we separate the sensor results to two parts: one for thehorizontal direction and another one for the vertical direction (x and ydirections respectively shown in FIG. 1). In the experiment, we find thestatistics to support the sample as an optical sensor, such as theresolution, accuracy and effective range. Firstly, using the sameexperiment configuration, we tested the sample in the horizontaldirection. In FIG. 11, it is a graph plotting the ratio against thedistance. The ratio represents the peak intensity of PFO divided by thepeak intensity of F8BT, and the aforementioned distance is the distancealong the horizontal direction. The figure shows that the effectiverange is 2.2 mm, i.e. from 0.4 mm to 2.6 mm in distance. The effectiverange is defined as the ratio that is not identical to each other and isunder the same trend. After calculation, the accuracy is ±0.11 mm andthe defined resolution is 0.25 mm. Along to the horizontal direction,the lasing spectra is the same as the one shown in FIG. 12, both ASEpeak being affected by the different positions of fiber.

For the vertical direction, we use the original ASEPFO and ASEF8BT peakintensities to replace the ratio as a parameter for the sensor. It isbecause along this direction the peak intensities are both decreased asthe distance increased. Thus, the ratio between both peak intensitiesremains the same, and it is no longer suitable to be a characterizingfactor of the sensor. In FIG. 13, it shows PFO and F8BT intensitiesagainst the distance along the vertical direction. The figure shows thatthe effective range is 60 mm, i.e. from 6 mm to 66 mm in distance. Theeffective range is defined to be the same as before. After calculation,the accuracy is ±3.8 mm and the defined resolution is 8 mm. In thevertical direction, the lasing spectra shows that both ASE peak wasdecreased when the detector was away from the sample (as shown in FIG.14).

Findings and the Present Invention

We have demonstrated a device made of cascaded organic thin films. TheASE from the two materials can be simultaneously obtained after beingpumped by optical laser. The emission spectrum of ASE was achieved inthe far field with tunable color. In both the vertical and thehorizontal directions, we have shown that the device that can be used asa distance sensor.

Based on the findings, the present invention is detailed as follows.

The present invention provides a system for measuring displacements andmovements, wherein said measured displacements include very finedisplacements and said measured movements include very minute movements.The system comprises one or more measuring means at least configured totune multiple color emissions from a laser such that the tuned multiplecolor emissions of the laser are used to measure said displacements andsaid movements. Said laser comprises an organic laser and/or a cascadedorganic laser. In particular, said system is scalable in order tosupport the measuring of displacements and movements across one or morephysical/geographical spaces including very large physical and/orgeographical spaces.

Optionally, the system further comprises a thin film laser generatingdevice for generating said laser. The system may further comprise blueand green emission organic semiconductors for generating said organiclaser. It is also optional that the system further comprises lasersensors for sensing said laser wherein said laser sensors compriseorganic laser sensors and/or cascaded organic laser sensors. Said lasersensors may or may not require any power for operation, or may bepassive devices.

One advantage of the system is that the system is configurable formeasuring one or more directions simultaneously.

The system is configurable for position and vibration measurements aswell as for measurements of rotational displacements/movements and ofangular displacements/movements.

The present invention also provides a method for measuring displacementsand movements. Said measured displacements include very finedisplacements and said measured movements include very minute movements.One or more directions may be measured simultaneously by the method. Themethod comprises tuning multiple color emissions from a laser such thatthe tuned multiple color emissions of the laser are used to measure saiddisplacements and said movements. Said laser comprises an organic laserand/or a cascaded organic laser. In addition, said method is scalable inorder to support the measuring of displacements and movements across oneor more physical/geographical spaces including very large physicaland/or geographical spaces.

Said measured displacements and/or said measured movements may includeone or more of: rotational displacements; rotational movements; angulardisplacements; and angular movements.

Optionally, said laser is generated by a thin film laser generatingdevice. It is also optional that said organic laser is generated atleast from blue and green emission organic semiconductors, and thatlaser sensors are used for sensing said laser where said laser sensorscomprise organic laser sensors and/or cascaded organic laser sensors.Said laser sensors may or may not require any power for operation.

INDUSTRIAL APPLICABILITY

The objective of the presently claimed invention is to provide a methodto tune multiple color emissions from organic laser and using suchtuning to measure displacements and movements. More particularly, itrelates to the use of cascaded organic laser to produce tunable multiplecolor emissions that is used to measure very fine displacements andmovements in physical spaces. The invention has application in providingaccurate and fine measure of displacements and movements in physicalspaces for applications wherein such fine movements are of interest.

What we claim is:
 1. A method for measuring displacements and movements,comprising: tuning multiple color emissions from a tunable amplifiedspontaneous emission (ASE) laser source having at least two lasersources excited by a single pump laser such that the tuned multiplecolor emissions of the laser sources are used to measure saiddisplacements and said movements; wherein said at least two lasersources comprise two organic lasers that are fabricated on silicasubstrates and are bound together, at the surfaces opposite to thesilica substrates, vis an optically clear adhesive; wherein the multiplecolor emissions spectra is tunable almost linearly in CommissionInternationale d'Eclairage (CIE) coordinates by spatially choosing themultiple color emissions signals.
 2. The method according to claim 1,wherein said organic laser is generated by a thin film laser generatingdevice.
 3. The method according to claim 1, wherein said organic laseris generated at least from blue and green emission organicsemiconductors.
 4. The method according to claim 1, wherein lasersensors are used for sensing said at least two laser sources, said lasersensors comprise an organic laser sensor.
 5. The method according toclaim 4 wherein said laser sensors do not require any power.
 6. Themethod according to claim 4 wherein said laser sensors are passivedevices.
 7. The method according to claim 1, wherein said measureddisplacements or said measured movements comprise rotationaldisplacements or rotational movements.
 8. The method according to claim1, wherein said measured displacements or said measured movementscomprise angular displacements or angular movements.
 9. A system formeasuring displacements and movements, comprising: a tunable amplifiedspontaneous emission (ASE) laser source having at least two tunablemultiple color laser sources excited by a single pump laser such thatthe tuned multiple color emissions of the laser sources are used tomeasure said displacements and said movements; wherein said at least twolaser sources comprises two organic lasers that are fabricated on silicasubstrates and are bound together, at the surfaces opposite to thesilica substrates, vis an optically clear adhesive; wherein the multiplecolor emissions spectra is tunable almost linearly in CommissionInternationale d'Eclairage (CIE) coordinates by spatially choosing themultiple color emissions signals.
 10. The system according to claim 9,further comprising a thin film laser generating device for generatingsaid organic laser.
 11. The system according to claim 9, furthercomprising blue and green emission organic semiconductors for generatingsaid organic laser.
 12. The system according to claim 9, furthercomprising laser sensors for sensing said at least two laser sourceswherein said laser sensors comprise organic laser sensors.
 13. Thesystem according to claim 12 wherein said laser sensors do not requireany power.
 14. The system according to claim 12 wherein said lasersensors are passive devices.
 15. The system according to claim 9,wherein said system is configured to measure said displacements or saidmovements comprising rotational displacements or rotational movements.16. The system according to claim 9, wherein said system is configuredto measure said displacements or said movements comprising angulardisplacements or angular movements.